Phosphorus oxychloride → 2-Chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,2-a]pyridine

HRID 1907352Notes

Reaction equation

HRID 1907352 reaction equation
Br.[NH:2]=[C:3]1[CH:8]=[CH:7][C:6]([B:9]2[O:13][C:12]([CH3:15])([CH3:14])[C:11]([CH3:17])([CH3:16])[O:10]2)=[CH:5][N:4]1[CH2:18][C:19](OCC)=O.O=P(Cl)(Cl)[Cl:26]>>[Cl:26][C:19]1[N:2]=[C:3]2[CH:8]=[CH:7][C:6]([B:9]3[O:13][C:12]([CH3:15])([CH3:14])[C:11]([CH3:17])([CH3:16])[O:10]3)=[CH:5][N:4]2[CH:18]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 86761542Ethyl [2-imino-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2H-pyridin-1-yl]acetate hydrobromide

Product 1

HCID 442323732-Chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,2-a]pyridine

Conditions

Temperature
105 °C

Procedure

8.78 g of ethyl [2-imino-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyridin-1-yl]acetate hydrobromide in 20 ml of POCl3 are placed in a round-bottomed flask. The reaction mixture is heated at 105° C. for 16 h, cooled to ambient temperature and concentrated under reduced pressure. The residue is taken up between dichloromethane and water at 0° C., and a 30% aqueous solution of NH4OH is added until a basic pH is obtained. The organic phase is separated, dried over magnesium sulphate and concentrated under reduced pressure. 4.3 g of compound are obtained.

Workup

  1. temperaturecooled to ambient temperature
  2. concentrationconcentrated under reduced pressure
  3. customis taken up between dichloromethane and water at 0° C.
  4. additiona 30% aqueous solution of NH4OH is added until a basic pH
  5. customis obtained
  6. customThe organic phase is separated
  7. dry with materialdried over magnesium sulphate
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-a90ab303fe6b4dd2857645ce7352544e
Source dataset
uspto-grants-2013_12
Patent number
US08598166B2

Reaction notes

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